What free and / or paid game master aids are available for a PC user running virtual games? [closed]

I’m running a d100 based game. Currently, we’re using Discord with DiceParser installed. I’ve poked around at www.Roll20.net in the past. What paid and/or free programs would you recommend for a game master using a PC to run a remote game? Some of my players are using android phones and some iPhones. My budget is very low but it would be great to see the high budget options too.