1. My very favorite, most used iPhone Photography App is Hipstamatic. It has a bit of a learning curve but is well worth it. There are new updates all of the time. It was first released in 2009 and I have been using it since then. If you want help learning Hipstamatic I have created a how to eBook called the Hipstamatic Lens/Film Guide ($3.99). You can purchase it from Lake Tree Press by clicking on the link below. The Hipstamatic app is $2.99 It is rated 4.7 stars out of 1.5 thousand reviews. You can't get much better than that!
2. For retouching landscapes, waterscapes and architecture I use the Touch Retouch app. Are power lines ruining your photo? Touch Retouch has a line removal tool that is pure magic! There is hardly a day that goes by that I don't use this app. It is $1.99 and is another highly rated app with 4.8 starts and 1.89 reviews. Wow! Now that's a winner. Touch Retouch was originally released in 2010 and I have used it for eight years.
3. For retouching faces I use Facetune. Why not Touch Retouch? Facetune has a lighter "touch". It makes people look like they've had a good night sleep and might be 5-10 years younger. It does not make them look like they have had a facelift gone bad. It also has a tool to easily brightening teeth and another for sharpening eyes. It was released in 2013 and is $3.99. It has a rating of 4.9 stars with 40.7 thousands reviews. It is definitely a hit! Next time you take a photo of an "older" friend, try Facetune. They will thank you.
4. Waterlogue was also released in 2013. It will take your photos and turn them into amazing watercolor images that can be printed. It was named as one of the App Store's Best in 2014. I love it and use it often. It does not have as high of rating or as many reviews (329 ratings, 4.6 stars). But everyone I have every shown it to thinks it is great and can't wait to try it. Cost is $3.99 and worth every penny.
5. There are a number of very good apps to place words onto images. The Typorama app is the one I return to again and again. I like how it makes the words more graphic. It includes several type layout options and you can in-app purchase more. The basic app is free. It has an exceptional 4.8 star rating with nearly 50 thousand review. That is just amazing.
6. This is a fairly new app for me. I have always recommended iResize for resizing images. However iResize seems to have left the iTunes store. I did some research and discovered Image Size. It has a 4.7 star rating with 5 thousand plus reviews. So far I like it. Also it is free.
7. The Diptic app is my favorite app for making photo collages. It is super easy to use. There are lots of template options and I find it reliable. I have used it since it first came out in 2010 and continue to use it often. It has a 4.7 star rating from 673 reviewers. The cost is $2.99.
8. You know how when you photograph a tall building the perspective gets off with the top of the building kind of looking pointy? Well there is an app to fix that. It's called Skwrt. I use it all the time for churches in Mexico. You can see a copy of how well it works here. It was released in 2014 but I only discovered it a couple of years ago when I came to Mexico and wanted better photos of church plazas. It cost $1.99. It only has a 3.6 star rating from 35 reviews. Never the less, I find it to be super handy and easy to use. Although I only use the one perspective tool. I still think it is well work $1.99.
9. You can do all kinds of things with Image Blender like make double exposures and photos within photos. However, I use it mostly for blending an original photo with a painted version. Sometime I think apps that turn your photos into paintings are a little heavy handed. Image Blender solves this problem for me. It costs $3.99, has a 4.9 star rating with 775 reviews. This is definitely a must have app. It was released in 2011 and is updated regularly.
10. I don't use Mextures quite as often as I do these other apps. However if I have a photo that's kind of boring with flat lighting, I will run it through Mextures. There is a tiny bit of a learning curve as Mextures works in layers. It is, however worth the effort. It is only $1.99. It was released in 2013, has a 4.0 rating with 66 reviews... not real well known but handy.
So that's my current Top Ten List for My Most Used iPhone Photography Apps. I have purchased an embarrassing number of iPhone Photography apps over the years. Hope this helps you not spend as much money as I have.
Also... a shameful promotion... I spent a year testing apps and wrote the iPhoneography Wow! eBook. I released at the beginning of this year. You can find it at Lake Tree Press for $4.99.