Putting together a well thought out and well executed user interface is only half of the challenge you’ll face in trying to sell your idea to the client. Whether your client expects rough wireframes or high fidelity screen shots, the challenge is often having them understand the workflow and how a user will interact with the finished product. To some extent the client will need a solid relationship with the developer and trust in his abilities to execute them. But at the same time, involving the client in UX planning can eliminate confusion later on in the project, and save time and money for everyone involved, as the scope can be solidified in the early planning stages.
Cacoo is intended more as a way for you to easily put together diagrams for the planning of your site or app. Sitemaps and Flowcharts are a breeze with this app, but when it comes to showing working screens or interface layouts, you might want to try another option.
Balsamiq’s large following is due in part to its easy to use interface and extensive library of components for mobile and web. The sketchy appearance will direct clients away from the design details and focus on workflow and user experience BEFORE you get to visuals, which will be a blessing.
Mockingbird keeps it simple with clean website components and an easy to use interface, but has added support for linking layouts together helping clients to get a real sense of moving through the site or app without ever seeing the design. This focus on user experience helps nail down the finer details quickly, while the ability to export all screens to a PDF is a feature clients and developers alike will appreciate.
Mockflow boasts the same standard features as Mockingbird and Balsamiq, but with the addition of the ability to export to HTML5. A companion desktop app makes designing on the go even easier since you’ll need no internet connection to continue working.
To be sure, the first four are intended for planning and design of the skeleton of your app or website interface. Comparing them to Invision is not an apples-to-apples comparison. That being said, however, whenever we are called on to present a semi-working, full fidelity mockup, we have been using Invision with great results. It allows us to get as close as possible to a fully functioning app before we even look at the development stage. Linking full color, full resolution screens and having them run at full resolution right on the device is a huge plus for us. Clients love that we are able to add Home Screen icons and custom loading screen, making it appear as if the app is already functioning locally (iOS devices). The commenting and collaboration tools allow the designer to leave notes for the developers on how the interface will function, collect feedback from the client and implement it on the spot, long before any code is written. One of the major improvements we would like to see is the ability to easily export a PDF with all the screenshots necessary to provide a concise, well put together printout of the interface for client records.