Hey! So, we are using wild magic optional rules, but rolling the d100 dice and looking up the roll in wild magic chart takes a bit long time.
Plus, some of the effects in that chart are just lame, like summoning a musical instrument, so i wanted to replace some effects with my own and present it to gm for approval.
May be some experienced players know of something like this?
Sounds like you'd be best off writing/printing your own chart.
I don't know of any programs like that.
The best I can suggest is using a Microsoft application like Word or Excel and creating your own chart that way. It's not exactly free, but the best part about it is that you can edit the chart until the GM gives the okay, and then print out a final copy (or a few for everyone's reference).
It seems silly and does require some experience, but to be honest, it's perhaps the most open-ended means to do so, and allows for the most customization possible.
There are also free office programs that aren't Microsoft, if that matters.
Google Docs is free and would allow your GM to easily add his/her own entries.