If you have the LEGO BB-8 Building Kit, you can modify it to add remote control functionality. It takes some work and extras like the SBRICK, but Sariel’s LEGO Workshop provides detailed instructions on how to get everything built as well as how to set it up on your phone. If you own a PlayStation 4, you can even set up the BB-8 RC to use your PS4 controller as an input. It’s important to note that BB-8 RC does not roll around like in the movies, but has wheels it rolls on. This makes it great on flat hard surfaces, but it makes it hard if not impossible to work on rugs and carpet. Is this a mod you’d be interested in?