How to make my instagram pics POP? What apps can i use to make my iphone 4 pics look HiDef?

Okay i like using instagram alot. And hey! Its summer, i'm in university and i use instagram when i'm bored. I'm not like super obsessed with it. I just wanna know what apps i can use to make my pics POP? I have an iphone 4… And it takes alot of editing for me to make my current pics to look good. I want my photos to look like it came out of a HiDef camera

I like to add borders or effects, just to make them different as they stand out that way.