i have a lot of android development experience, you can ask for screenshots of my previous apps, i can implement php backend servers or google firebase for chat, and geo-location implementation is easy, login/register can also be done through firebase or php server, have experience with all those, i will use 000webhost during development if php severs are required, then later i will help you switch to a paid hosting for server. But if i use firebase, then you will not need to pay for any hosting services, google firebase is completely free!
sort and filtering is easy, its not a big deal!