If your app is going to bring value to users, a very simple and clean design should do the trick.
You still need to show interest in UI design if you’re going to make an indie app as creating a clean design is harder than it looks. I must admit my apps could look better! Have a look at well-designed apps and think about which details make them feel well-designed.
I tend to focus on:
- Giving each element on screen space to breathe around it so that it doesn’t feel too crammed in or stuck to the sides
- Consistent spacings and sizes between elements
- As few different font sizes as possible
- Visual feedback when a button is pressed
- Simple animations when some elements appear on the screen
- General visual consistency between screens
Focus on a few (not many) details that seem most important to you but be prepared to spend a lot of time adjusting them and checking the result on all screen sizes. I find it useful to keep a list of all the different iOS screen sizes displayed in my office to make sure I’m not forgetting one. You can find it here.
I also like to put myself in the shoes of a user struggling with smartphones. Can you understand what’s on the screen? In my opinion standard designs advocated by Apple and Google tend to favor users who are very familiar with smartphones. A burger menu without any text to describe it as a menu can be confusing to some users, for example. Don’t be afraid to deviate from a shiny modern design.
In my opinion, indie apps need to be easier to use than big established apps. Instagram can make finding the ‘new post’ button confusing because it already has a huge user base and because it can benefit from promoting a strategic new feature instead. You can’t do that yet!
Moving onto the color palette now: if you’re not a graphic designer, just find a good color palette website on http://www.uigoodies.com/ and pick one. Don’t try picking colors by yourself at home 😉