I chose to do an heuristic evaluation of the Meetup iPhone app using about five of Nielsen's 10 usability heuristics for UI design. For anyone who doesn't know, Meetup allows you to connect and host events with other people who have similar interests and skills. I’ve been using Meetup for about four years, and downloaded the app about a year ago.

1. Visibility of system status:
I wasn't fast enough to catch a screen shot, but when loading a new page an animated progress bar appears to let the user know something's happening. Visually I like it, but I think it's too subtle. I felt a few seconds of confusion when the page didn't load automatically even though I've used the app for a while and have seen the progress bar hundreds of times. It wouldn't look as nice and minimal, but making it bolder or in the middle of the page may prevent people from assuming the app is frozen, even if just for a few seconds.

2. Match between the system and the real world:
The icons on the menu bar are supported by text, so there's not much confusion there. If the text wern't there I probably wouldn't be able to quickly match the flag icon with "groups," though having only five menu options would lead me there eventually. Most of the app seems pretty clear, except for the filter icon in the top left of the calendar. This is actually the first time I've ever noticed it since the icon doesn't match any icon or menu I've seen before. Perhaps if it looked more like the traditional hamburger menu I would've tried it out a while ago.

3. User control and freedom & 4. Error prevention: 
Meetup does this very well. Between the static menu, search icon, and back button I am confident that I can eventually find what I need and undo any mistakes.

5. Recognition:
I searched for topics in the group section and the key word remained in the search bar so I didn't have to remember what I typed in. Once I clicked on a pre-selected filter the location and distance were hidden until I clicked on the search bar to edit, which may or may not be intutitive to other users. I appreciated that the search bar remained static as a reminder of my selected topic while I scrolled down to view the different groups.

Insights & Improvements:
Overall I really like Meetup's app and generally prefer it to their website, mainly for convenience. One thing their app is missing is a calendar feature that looks further out in the future. Right now the calendar pulls up the current date and you scroll down to see the next few days. You can keep scrolling, but this would be way too tedious if I were looking for meetups months in advance (perhaps if I were planning a vacation and wanted to find local meetups by date instead of topic). This probably isn't a priority since Meetup is more about locals meeting locals, but I think it'd be handy nonetheless.

I also appreciate that Meetup allows you to filter your email notifications per group. There are some groups that I want to hear from weekly, and some that I never want to get an email from, so I'm constantly updating this in my profile.

If you haven't tried Meetup yet I'd definitely recommend it. There's a group out there for everyone.