I'm not aware of any such app that specifically matches your query but is it that important to you to check the battery capacity on a device left at home?
Keep in mind if someone does have a viable suggestion for you (I'm assuming some kind of remote access utility you need to set up on both devices that link to each other either over WiFi or mobile data), that also means instead of letting your device at home stay in its power-saving sleep state you'll be remotely waking it up every time you want to check on it, using that battery's charge, just to check on its battery charge level.