At Easter I make a lot of chocolate bunnies, chicks, etc and found this tool on ebay years ago (it's also on Amazon.com). I love it for painting chocolate. It takes a while to warm up but you just drop in your colored candy melts and it melts it and keeps it soft for as long as you need it. The individual cups come out for cleaning or if you want to store the remaining chocolate for another day. It is electric but does not get hot enough to burn you so I use it with my grandchildren also.
When I am doing piping with chocolate I use a heating pad to rest the pastry bag on when I'm not using it. This helps keep it warm and flowing.