The program is really simple. To the right, there's a huge list with more than 50 different templates with the most popular memes (Y U NO, Bear Grylls, Chemistry Cat, Philosoraptor, etc.). To the left, there are two text fields where you can enter words for the upper and lower lines.
Once you finish creating your meme, you can save it in PNG format on your hard drive, or upload it directly to Imgur or reddit.
iMeme might not seem very useful for some people, but those who appreciate it will find it to be an endless source of fun.