Save Work
iPhone Icon Maker allows you to save your work and resume working on icons later, exactly how you left them off! This took a very very very long time to implement, and it is likely that there are still some bugs somewhere.
To edit an icon, tap on it from your icon list. This restores the icon file. Do your changes.
To save your changes, tap the blue “SAVE” button in top right. This saves the local changes. There’s still one more step to do:
Next, you need to name your icon on the preview screen. This creates a local folder for your icon files and stores all the generated icons in that file.
From the preview screen you can also email yourself all the icons you need – 512, 144, 114, 72, 57, as well as 58,29 and 50 pixels white, transparent PNG. I’m pre-rounding corners based on Apple provided recommendations, so your icons would look the same regardless of whether they are displayed by apple or are listed on your websites, etc.
iPhone Icon Maker++ pushes iOS to it’s limit. There are a lot of views, transforms and details that need to be saved. The iOS is capable of saving it, but the progress may be slow on iPod Touch and older devices. I do not support iPhone 3GS. If you somehow get it on that device, the app is unlikely to work as expected.
Dropbox Sync
Last, but not least, you can save your work progress, along with all your generated icons using Dropbox Sync. To do so, tap the dropbox button on your icon list.
[notice]For best results, you need to have the dropbox app installed. There have been numerous complaints that the dropbox web authentication API does not work. Logging in with the dropbox app works every time.[/notice]

This is a preview of how your icon would look in the iPhone app store
To start the sync process, you need to authorize the icon maker app to access a folder within dropbox. I can only see one folder, and the app manages the contents of that folder.
Next, tap the perform sync button. The total number of tasks remaining would be displayed. Each task is the upload/download or delete operation. Some of the tasks are instant, others are lengthy. It is recommended that you sync on wifi.
Dropbox sync puts all the icon files, along with the icon JSON file and a camera/logo image to dropbox. You can sync another app with the same dropbox account, it will download all the files, deserialize the JSON and create exactly the same icon file on another device! You can then continue work on your icon, but be warned – the latest modified file always wins. There’s no merging changes, and it’s possible to overwrite each other’s changes.
Please spread the word!
The Icon Maker app does not have the luxury of having a keyword optimized website built for it (yet). As such, I rely on word of mouth and your feedback to promote this app. At 5$, this app costs far less than any icon making service, or a stock photo. I hope you enjoy using the app. Good luck with your app store sales!