dashware is very good,it's free now aswell.also if ou have any lap time data you can overlay the data onto the vid,and using the software,add different dash screens
If you have a go pro their free software is very good. If you want to spend money there are plenty of video software out there. But I have only used Windows movie maker when on PC and the equivalent on my newer Mac
I've been using Track Addict on my Android phone for GPS data, which is free. Then used a program called RaceRender3 to link it all together including a rear facing camera video stream. Pretty easy to use only tricky bit is getting front and rear videos synchronised. Link below to first one I did.