I’ve made, tinkered and played around with hundreds of Android Projects in my mayhem “Android” days (early 2012 ~ mid 2015) on my beloved Nexus One before I finally had to let go of it. I loved (and still do) building Apps that mostly interacted wirelessly with Hardware (mostly Arduino) either through Bluetooth/WiFi.
I uploaded most of my Projects on BitBucket (an year ago) and you can grab them off here: https://bitbucket.org/anwaarullah/android/src
Some of them are awesome, and some of them are silly apps (and u can hopefully ignore those 😛 ).
I’m around if you need any help with these apps/projects 🙂
P.S: I only uploaded one of these projects on the PlayStore here: https://play.google.com/store/apps/details?id=com.sample.user