I don't know if they have an app, but definitely check out 3dplans.com. They have been huge supporters of this community for years, and we've only heard good things about them.
Can anyone recommend a good app to create a floor plan? I have used the Stanley app which is delightfully user-friendly but not-so-delightfully requires a subscription to upload them into the computer or access them in any way outside of the app.
I'd also like to know if anyone can recommend a good app that would work like measuring tape to measure wall-to-wall distance.