Redesigning Whoscall In-app-purchase experience

Project type

Solo project of conversion optimization


2018 March - May


Executing design at all stage from concept to the end, including planning flow, prototype, and visual mock-up.

Tools used

Sketch, InVision prototype, Illustration

Define problem, identify goal.

Whoscall is a caller-ID identification app. Identification is free for use, then it provide paid version as Premium which contains ad-free and auto-update database. In order to be independent from advertisement incomes, the goal of this project is to improve the paid-user conversion. 

Our challenges

According to user research we had done before, Premium plan is not attractive to our users, the reasons are:

  • Basic plan is more than enough : Free version already serves the must-have function.

  • Not aware of the product: User don't know what benefits they could have after purchasing, so it's hard for them to evaluate the value and make decision.


Resources and time are both limited, there is no expect to develop new feature for premium plan, also no time for planning and executing the user research.


We've identified the problem and have some insights from the research we collected before. Then, we used HMW statement to turn challenge into opportunities for design.

How might we

increase people's attempt to purchase Premium plan

by making it more attractive?

by letting them aware of the benefits they might receive?

Apply methodology
Visualize the user journey to find applicable scenario and touch point

I divide users into three groups: new users, previous basic users, and previous Premium users, and draw out their journey in our app. Base on different stage of journey, brainstorming the different ways to approach our statements.

Set up hypothesis

By brainstorming ideation, we made up top two hypothesis.

  • By providing free trial, users are more likely to purchase the Premium plan.
    Free Trial is like free sample strategy. If user has experienced the product and has positive memories, he/she will have higher chances to purchase the product.

  • By showing the enough information can help user make the decision.

Building the experiences by flow

New user | Free trial as reward after tiring onboarding

The scenario we decide for free trial experiment is after the onboarding process. The target user is new user. As we think the process is lengthy and tiring for  new users, we can reward them by offering free trial of our premium plan, which can let user experience the product. After the end of free trial, they can fill out the feedback form to get the extra discount for buying Premium plan in limited time.

Existing user | Make product appealing

As the previous design of Premium introduction page was too simple without enough infomation, we tried to optimize the content by showing enough information to help user make decision, and use the comparison to show the benefits they can have after purchasing. 

Previous Design

Improved Design

 show comparison

Also, adding new entrances which direct to Premium introduction page, as the Premium introduction page was hidden in the drawer only. There was no other place reveal the product, or provide the entrance heading to product, so we decide to add some interface change to trigger user's curiosity. 

Previous Design

Improved Design

new section add

How to measure success | Observe key metrics and iterations

The key metrics for this project is the conversion rate of paid users. However, we didn't actually define to what amount of number can be seen as success ( We didn't have too much experience about doing experiment before). But we keep the usage data and track every step, as we can observe the data for future.

Results and learnings

After slightly redesign the Premium introduction page, the number of page view increase nearly 30%, and there are 8% of new subscribers came from the new entrance.

In the other side, during nearly half year, there was 20-30 new paid user after having the free trial (  0.1% of total new users). That was a really horrible numbers.😅

Overall, I don't take this project as successful project, as there are few things we missed out, in terms of defining successful metrics, and considering develop scope. The hypothesis came from 'previous' user research is not a good idea. If the project scope was this small, it was better to slightly change the interface, instead of building the new flow ( free trial), as the free trial hypothesis just came from theoretical assumptions (or we need to narrow down the size to test the water, like do some fake door to quickly test the idea and get some feedbacks). 

What's next?

There is a lot more to do for this project. Our focus will be on improving the product value in the future. As we deeply know the issue we need to deal with is the Premium product itself. There should be more things to be done, for example, define our hard-core user and dig out potential pain point for them, user groups...etc.

Thanks my team being so supportive from concept to the end! 😚