Sorry if this has already been posted somewhere else, but I was hoping someone could help me understand what the differences are between these smartapps, what benefits and challenges each ones have over others as well which one people use & recommend most.
Thanks!
Iām not familiar with echo helper, but both askAlexa and EchoSistant are very popular for community members who are more technical. They have somewhat different feature sets, so you just need to explore each one to see which is the best match for your own needs.
If by chance you meant āAlexa helperā rather than āEcho helper,ā then those are two different projects from the same developer. 
See the following thread for that comparison discussion:
Two of the 3 mention (it is actually Alexa Helper) were created by me. I will go through the other two and I am sure the author of the third will go into their details:
Alexa Helper-This uses the native integration with Alexa and SmartThings to give you basic control over items that canāt be controlled by the native integration. For example, you can open or close doors with this app, or lock/unlock doors. However, it has to use the context of on/off since that is how the native integration worksā¦You basically set up virtual switches (proxies) and when you control them, it controls other items. Finally, you can use this structure to also trigger routines and modes. If you have just one or two items to control or want to control a simple mode change, this is probably the easiest one to install and get working, but syntax-wise it is āclunkyā to say āAlexa, turn on Garage openāā¦But some people have gotten creative with the naming so it isnāt a issue. The full documentation can be found here: http://thingsthataresmart.wiki/index.php?title=Alexa_Helper
Ask Alexa-This is the more āpremiumā entry into the Alexa control. The installation is a bit more difficult, but I have a document that has been very well received and have gotten thousands (literally) of people up and running: http://thingsthataresmart.wiki/index.php?title=Ask_Alexa. The obvious advantage of this app, outside of its maturity (it have been out for over a year and half) is it allows you to fine tune the control of your house. I have over 50 items in my house and I use Ask Alexa to control many aspects of them, from complex macros (do this, then this, then that). There is some REALLY creative stuff people have used Ask Alexa with. Finally, you will find no other app that has external (other developer support) than Ask Alexa. Amazon has push notification coming out soon, and Ask Alexa uses a concept of message queues to allow you to have other smartapps send messages to individual queues that can then be read back to you. Currently, there are over 15 other smartapps that have integrated their with Ask Alexa. The downside, again, is the very complex installation procedure (which other Alexa skill apps also have), and the fact you have to initiate a skill name to activate it. I have "Smartthingsā as my app name, so I say āAlexa, tell SmartThings to open the garage doorā. You can also set up multiple versions of the skill to give each room a name, so you could have items set up like āAlexa, tell the master bath to turn on the fanā. Using macros, you can get some natural conversational feedback. Finally, I just recently added a schedules feature to the program that allows you to send messages to the message queue (and eventually through push to the device itself) to remind you of birthdays, anniversaries, appointments, etc. I have been told this is one of the overall best scheduling programs for SmartThings because of its ability to remind you before an appointment, not just the time OF the appointment.
At the end of the day, I recommend if you are on the fence to install each of them one at a time and see which one fits your needs.
Hope this is helpful.
The biggest advantage of EchoSistant, is the use of free text, which makes things a lot easier for the end user. Natural expressions are available from the begining with no additional set up needed. You could say Alexa is too hot in my home, and Alexa will respond by adjusting your AC. Or Alexa is too dark in the bedroom, and Alexa will respond by turning the lights on.
Also, EchoSistant offers a friendlier way of identifying Alexa enabled devices by linking them to a Profile. This enables users to send targeted messages between rooms (intercom like features).
You could find a great discussion about EchoSistant and Ask Alexa on the following threadā¦
Iāve got Ask Alexa installed already, but Iām wondering what you mean with the scheduling and Alexa reminding about appointments or whatever - how do you do this? All I really know how to do with it is to have Alexa provide device status. I really like the smartapp, but unsure of any other capabilities.
Gene,
Great question as I am always updating and improving the system. Just recently I updated the app with a new extension called āSchedulesā. You can read about it here. If you are on any version less than 2.2.6 you will need to upgrade all of the components (Lambda, developer slots, IDE code) to use this, but it is well worth it. You can read more about it here:
http://thingsthataresmart.wiki/index.php?title=Ask_Alexa_-_Schedules
However, the high level summary is that you can schedule actions (and reminders BEFORE the action, something that is quite important!) within Ask Alexa. While most will use the āactionā to be just a verbal reminder, Ask Alexa can actually schedule REAL actions (run CoRE Macros, play a voice report, turn on lights, etc.) Of course, the classics uses are still hereā¦ For example, letās say you have an annual event (i.e. birthday and anniversary) of someone in your family. Simple use your app to set a reminder and a new message will appear in the message queue you designate to remind you of this. In addition, for those of you in volatile weather areas, you can also utilize the advisory weather report to play (on ST connected speakers or put a message in your message queue) when adverse weather is forecasted. While Amazon allows you to set reminders via voice, I actually feel setting up complex schedules with the app (i.e. VISUALLY) is the way to go. There are SO many things you can do with this extension, and a plethora of ways you can set a schedule (one time, recurring, even real CRON expressions).
If you need any assistance upgrading, feel free to reach out to meā¦
I hope this doesnāt sound like a dumb question, but how do you upgrade smartapps because Iāve got version 2.2.0?
I wish there was an upgrade button 
Basically, it is a full re-install from an conceptual level; the only difference is that you donāt have to create new accounts or anything else.
Again, the document will help, but here is your high level upgrade tasks:
While 3 steps, coming from such an old version will require some planningā¦especially if you have voice and weather reports created. If you donāt, then it SHOULD be smooth sailing (famous last words) 
I still canāt get over this 
Wish someone made it work with all sorts of names, just like in this ad:
Hello and thanks for asking about all of these apps!
EchoSistant has been designed around the concept of making Alexa work for you instead if you working for Alexa. What I mean by that is that you do not have to remember specific phrases to make things happen. You create a profile based on the room of your home, for example, the living room.
A typical conversation with Alexa goes like this:
Alexa, I am reading in the living room
Ok, adjusting the lights for you in the living room, would you like anything else?
Yes, it is to warm.
Ok, adjusting the cooling, anything else?
Slow down the ceiling fan
Ok, setting the ceiling fan to medium, anything else?
No thank you
It had been my pleasure, goodbye
But your spouse may say itās to hot, instead of to warmā¦ And that is ok too.
EchoSistant also gives phenomenal feedback about things in your homeā¦
Alexa, ask home is the garage door closed.
Yes, the garage door is closed.
EchoSistant is integrated with CoRE and soon to be WebCoRE, the most powerful control app in the st environment. It is also integrated with RemindR, also the most powerful notifications app in ST.
The install is rather daunting, but there have been several hundred people before you that have been able to accomplish the feat!
Again, thanks for your interest and donāt forget to ask anymore questions!
Grandpa: Aljazeera, turn up the heat
Alexa: The NSA skill responded that this command is illegal, a friendly FBI squad has been dispatched
For me:
Alexa, tell smartthings sleep
I donāt know that
Alexa, tell smartthings sleep
I donāt know that
Alexa, tell smartthings sleep
Make sure you have enabled the developers section of the askalexa app, would you like to try again?
Alexa, tell smartthings sleep
Hmmm Iām not sure
Alexa, tell smartthings sleep
-nothing happens-
Alexa, tell smartthings sleep
I donāt know that
Alexa, tell smartthings sleep
ok Iāll run the sleep routine -lights turn off sometimes leaving 1 one, nest temp is adjusted, ST is put in alarm stay mode-
Alexa, tell smartthings sleep (in order to completely run the routine to turn all lights off)
I donāt know that
Alexa, tell smartthings sleep
I donāt know that
Alexa, tell smartthings sleep
ok -last light turns off-
Sadly this is becoming more and more common occurrence for me and not just with the sleep routine but any command I tell Alexa. I donāt think this is an askAlexa issue, itās an Amazon Alexa issue.
Yes I use askAlexa, but I donāt think thatās the reason for the non compliance by Alexa.
There is always a chance you would confuse Alexa if you authorize a custom skill on top of the native integration for the same devices. If your routine doesnāt have locks, then to use native integration you must say Alexa turn on sleep. If you want to use a custom skill, I would deathorize the routines in the native app and just use the cust skill to run them.
My Alexa is just confused or being a pain. When I say a command to directly control something like a light or Nest thermostat she complies. When Alexa has to integrate with ST thatās when the problems seem to arise.
I just changed the invocation word for ST things from smartthings to house. She seemed to comply with commands using that. Iāll test it for a couple of days as Alexa, tell house ā¦ instead of smartthings.
Certain words are indeed bound to confuse any skilllā¦However, sleep is not one of themā¦so the question comes upā¦what is āsleepā in the context of your environment? If sleep is a macro or routine, this name MUST be in your Amazon Developers slot. From the looks of your output, if you are accurately transcribing it, most of those arenāt even activating Ask Alexaā¦Some are (i.e. #3), but #4, #5, etc are not a responses Ask Alexa would give. I recommend looking at your Live Logging or Amazon app to see what Alexa THINKS you are saying.
As a test, I just set this up myself with a macro called āsleepā. I added this to the developer slots. Every single one of them worked with different combinations (ask, tell, etc).
I then created a routine called Sleep to test it. I had to move the āsleepā verb from the macros slot to the SHParms, but these worked as well.
Letās move this to the Ask Alexa thread if you would like to troubleshoot this more. The original intent of this give Gene a good comparison of the apps out thereā¦Sounds like he has that now.
I did not intend to sidetrack this thread. Was just showing my interaction issues and like I said I do not think it is an askAlexa problem. askAlexa has been very useful for my needs.
No problemā¦thanks for the PMā¦For those that are interested we determined this is NOT Ask Alexa, but a fundamental issue with how Alexa is hearing the commands. Changing the invocation word does help.
Thanks to @tpip for working with me on this so we could validate where the issue is.