Try the old 3DR Solo app on a Chromebook, it might work. Or an older phone as was already suggested. Or just start your camera recording manually on the ground, fly it and have fun while you're saving up for Solex and purchase it when you have the funds. I understand the "don't want to spend it" part, but in the grand scheme of the hobby, it's honestly not over the top.
If you have an iOS device, the Side Pilot app is a considerably less expensive option as well.