After being pulled from the App Store last week, popular photo-sharing app 500px has made its return with an updated version.

The major addition to version 2.0.3 of the app is a “Report This Photo” button for users to flag questionable content. The update also fixes an issue that would redirect a user after logging in and an issue that resulted in partially downloaded photos.

Also, the app now carries the designation that content is for users 17 and older because of “frequent/intense sexual content or nudity.”

The 500px app is universal for both the iPhone/iPod touch and iPad. It can be downloaded in the App Store now.

Apple yanked the app last week and commented on its removal:

The app was removed from the App Store for featuring pornographic images and material, a clear violation of our guidelines. We also received customer complaints about possible child pornography. We’ve asked the developer to put safeguards in place to prevent pornographic images and material in their app.

But Apple seems to be happy enough with the changes made to the app to allow it back in the store.

Another app, Vine, also made unwanted headlines this week when a pornographic video was featured in the app. Apple didn’t pull Vine but did remove it from the store’s Featured section.

Our own Bryan Wolfe had an interesting take on the issue, saying yesterday that Apple should ditch its “selective” censorship policies and let the market decide whether apps like Vine should stay in the App Store.