Is there a way to integrate iHome iSS50 5-in-1 Smartmonitor with ST?
Unfortunately not at the present time. It only works with its own app or with HomeKit.
You could use an iHome plug as a “man in the middle” by having the ihome app turn on The plug when the sensor reaches a target value and then have that plug coming on trigger something in SmartThings. But it means dedicating a device just for that purpose so most people won’t want to do it. But if you did want to have a sensor value trigger the plug plus have some other things happen in SmartThings, it might be worth it.
https://support.smartthings.com/hc/en-us/articles/211523263-iHome-SmartPlug
What I did was create a virtual switch in Smartthings for each of the functions of all iSS50’s I own (ie a virtual switch labelled motion, temperature, etc). I then connected my iHome account to IFTTT. Finally, I created an applet in IFTTT that connected the iHome scenario to the Smartthings virtual switch (If temperature goes above X°C, turn on virtual switch temperature. If temperature drops below X°C, turn off virtual switch temperature).
It’s pretty time consuming and you have to remember to create at least 2 applets per virtual switch (one to turn it ON and one to turn it OFF) but it works.