Frozen pops and ice cream are always great fun with kids. I enjoy getting the kids involved with the whole process. I use my electric ice cream maker, but if you have a manual ice cream maker that's great too. I have wonderful memories of making ice cream with my grandparents using an old hand-crank ice cream machine. It was great fun.
For the pops, you can simply use fruit juice that you have on hand and use ice cube trays to make Popsicles. Or, if you want to make a really healthy treat you can blend some fruits and make Popsicles out of the mixture. If you don't want to do that, you can just do it as smoothies. The great part about it is that there isn't a recipe that you need to follow. Just add strawberries, blueberries, bananas, etc. to a blender and keep adding ingredients until you find a smoothie taste that you love.
Have fun. Summer is a great time to experiment with fun treats for the kids. And since the kids can eat the treats outside, you don't have to worry about cleaning up the mess :)