I have a house with a 3 car garage. It isn't huge, there are two doors, one small, and one large. I know on the large side we can't put our two cars in, and open the car doors. There are still two doors, each with their own openers. The remote controls in the cars work great, but you need two, if you want to open both doors. Yes, I know they sell learning controls that will open both, but what about when you just want to open the door when not in the car? I have tools and such in the garage, and sometimes I need something, and the car may be in the garage.
Once I had all the Arduino hardware working, it was time to do something quick with the Android. The ArduDriod has an OK interface, but I wanted something that looked like it belong. I didn't want to do a full blown app, so I looked at my options. I ended up choosing App Inventor. It is probably as much work as writing an app, since I had a lot to learn, but I was able to learn the app inventor and as a result I have an app that will open and close the garage.
There are 3 buttons and a label. The buttons cause the relay corresponding to the door labeled to close for about a second. I have the project available if anyone would want it. It was done using app inventor 2. The protocol stillis the ArduDroid protocol, so I had a sketch I could start with.
If you want to try it, let me know, I'll share what I have.