I will be releasing a paid and unpaid version of my app on iPhone and Android. How should I name these two versions? Some popular choices I've seen are:
Does the wording change the user's perception of the quality of the app? For example, has online spam trained people to treat "free" with skepticism?
Not first option - It emphasizes free too much and users tend to think 'Hey - I've got something for free' and be happy with that to the point of making a point of not wanting to pay anything - however good the paid one is. Free can sound like it's a trial or severely limited - like 3 free levels in a game where the paid version has 100. Anyway - it might get downloaded in the millions and then you might want to charge a tiny sum (millions * tiny sum = bug sum!) and then you'll regret having called it Namezilla 'Free'.
Not the third option - Once you've got just the name Namezilla with no qualifier there's nothing obvious in the name that says there's a better version out there, so users forget about it.
That leaves the second option - well the Lite is good - it doesn't say it's free (even though it might be) so you might feel like you got a decent enough version but you accept that maybe it's not got 100% of the features it could if you paid. The Lite gently reminds you that there is a full version available - it's a little reminder every time you use it - without the harshness of the word free shouting at you.
As to whether you call the paid one Namezilla or Namezilla Plus or Namezilla Pro, well just think about if there is going to be an even more expensive one in the future - might it have to be called Namezilla Plus Plus or Namezilla ProPlus (one for the caffeine addicts out there!)
The 'plus' option, at least in the app store tends to not have to do with free/pay but rather if it's iphone/iphone+ipad. The 'plus' means it includes both versions in one app.
So that gives you lite and free or...
If you're only focused on the Apple App Store, I'd suggest not having two. Just have one. Put all the features into one app but have the paid features accessible via an in-app purchase.
I'm not a marketeer by any means, but I think the "Lite"/[No Suffix] option (Alternative 2) is the most common and most easily understood. I think it conveys the idea of the paid-for version being the "complete" version and the free one being a little lighter on functionality.
That said, in a lot of cases, the only difference is the presence or absence of ads. Just my tuppence, but I'd got the second option.
The questions that I think you want to address first are "What do you want the user to do?" and "What does the user expect?"
Do you have different markets for the two versions of the apps? Are you pushing some users towards one app and others to the second? Is there an upgrade path?
How does the functionality differ? Why would somebody want the "extra" functionality if there is any? Can you get those users to self-identify by the naming?
To pick an example from our domain. We don't have "OmniGraffle" and "OmniGraffle Plus" - we have "OmniGraffle" and "OmniGraffle Professional". Notice how using a more role based name automatically sets some expectations on the kind of user who'll be using that version.
Or look at the way the pricing bands on bid sketch are named. The "Freelancer", "Studio" and "Agency" labels immediately give major cues as to what levels of functionality the different bands expose.
Suffixes like "Lite" and "Free" only reveal that there are functionality and cost differences. The user then has to go dig out the implications. Are there ways that you can help them do that via the naming.
