Apple App Store

You've probably noticed more and more coloring books for adults popping up at retail stores recently. That's because it is a great way for grownups to take some time to relax and focus on art without having to be particularly artistic. There are some great coloring book apps built specifically for the iPad that cater to different techniques. I've got a list of the best coloring books for adults for all occasions.

• Pigment
• Lake
• ColorSaga Coloring book
• Recolor

Pigment

Pigment offers the most versatile coloring experience. You can color with a variety of tools, including pencils, markers, airbrushes, water colors, oil paints, and more. You can blend colors, including lighter on top of dark, and press light or hard to produce different thickness of strokes. There are hundreds of colors to choose from, each with a shading gradient so you can customize your hues.

There are three ways to color with Pigment. You can use Automatic, which will allow you to color wildly, but you will still stay within the lines, Freehand, which is like real-life coloring where you will go outside of the lines if you aren't careful, and Advanced, which lets you select multiple spots on an illustration to color in at once. This last option allows you to color across different sections, while only coloring the objects you want.

There are also a few tools that are not at all realistic, but can be loads of fun to work with. The Fade and Broom brushes create a unique shading on your illustrations and the Fill brush lets you simply tap to add color to an object.

The best part is that Pigment works beautifully with Apple Pencil to create shades and depth to each page you color.

There are dozens of free pages, and plenty of great tools, but if you are a coloring fanatic, you can subscribe to Pigment's premium service for hundreds of illustrations, additional brushes, and new coloring books each week.

If you color in real life and are looking to recreate that experience on your iPad, Pigment is the best app in the App Store.

Lake

Lake has the unique feature of being a coloring book for artists, by artists. Well, you don't actually have to be an artist, but if you are, you'll really appreciate the time and effort that each of these Instagram illustrators put into their work, work that you can make even more interesting with your own color creations.

Lake also has the unique feature of offering you the ability to purchase a 12-page coloring book by each artist, individually. The price you pay for that book goes directly to the artist, too. If you love every aspect of the app, you can subscribe to unlock everything. But, if you're more interested in picking your pages by artist, you can buy a book outright for $3.99.

The color palate is vast, with varying shades conveniently connected on a rotating wheel. You can start with red and switch to the lightest shade of pink or a deep reddish brown. Each page also comes with a pre-made color palate suggestion, curated by the artist who illustrated it.

You can pick from five different artist tools to work with, and you have the ability to adjust the brush size of each. You can also layer colors (except with the paint can), and choose whether to restrict or free up coloring outside the line.

If you feel good about supporting working artists, you won't want to skip this coloring book app. It's full of great illustrations and gets updated all of the time.

ColorSaga Coloring book

ColorSaga Tell us about a little girl and her painting life.ColorSaga offers a simple fill-in-the-object style of coloring so that you don't have to work as hard to get a beautiful illustration. You can choose from a few dozen hues or upgrade to a monthly subscription to unlock more than 100 different coloring books.

When you are finished coloring, you're definitely not done creating. our finished artwork can be shared to various social networking sites. You can also publish pages to the social networking for others to comment on, or even add their own colors to.

You can also create your own illustrations to color by creating artwork from pre-made stickers and backgrounds, or by taking a picture of something you've drawn in real life.

There are dozens of free pages, and plenty of great tools, but if you are a coloring fanatic, you can subscribe to ColorSaga's premium service for hundreds of illustrations, new coloring books each week.

If coloring can sometimes stress you out because of all of that movement you have to use with your hands, Colorfy will give you a pleasant experience without all of the scribbling action.

• Free - Download now

Recolor

Recolor takes the whole digital coloring thing to the next level with 3D objects that you can actually color all sides of. Grab a soda can or ceramic vase and turn it into a virtual work of art. There are more than a dozen categories with hundreds of illustrations.

Recolor uses the tap-to-fill style of coloring, which can be very helpful when you are trying to fill in those tiny objects. In addition to the flat color gamut, you can upgrade to gradients and "Live" colors, which make things have a sort of swirling effect.

You can submit your artwork to the Recolor gallery where others in the community can "Like" your stuff.

My favorite tool in Recolor, though, is the scanner. You can scan in illustrations and color them digitally. I have a couple of vintage Star Wars comic books that I've been afraid to jump into because I don't want to ruin their value. Recolor's scanner lets me color the pages without affecting the original book

If you like fill-in style coloring, but want a lot of hue options, give Recolor a try.

This means that you must have a Credit card details on your Apple ID.

Usually it will ask you to Verify your account details before you can download anything else.

If you have a billing address but no credit card details then you don't always have to Review account details.

But if you don't you will have to put in your credit card details again.

It's easy just follow the prompts and you'll be back in no time!

Apple use this to protect it's customers from fraud and people using your account without permission.