For instance, you could be asking "which country will charge me the least tax?" Look for a tax haven, like some of the Caribbean islands.
But you could equally be asking "which country will provide the fastest internet speeds?", in which case it's South Korea.
The list of considerations you might be using to filter your decision also includes paperwork (at start-up and ongoing), access to mentors, fastest access to the largest number of users, or even language and lifestyle (if you wanted to live or spend time in the country). Some of these will differ again depending on whether your online software will be B2C, B2B, or Enterprise focused.
Are any of those factors for you? Are there others?
EDIT: Removed some useless stuff.
As such, taxes, the associated paperwork trail, etc. can still be the driving factors when deciding where to incorporate. At a later stage the accessibility of additional funding may also be a point.
My (software) company is incorporated in Hong Kong for, among others, these reasons. But I neither live there nor work there.
There may be some advantages to incorporating abroad in order to take advantages of streamlined legislation - many Germans incorporate in the UK to avoid the complex and expensive GmbH - but trying to outsmart tax authorities just isn't worth the effort for a small startup.
When you ever want to take out more than this salary from that company, make sure you do so either through another company that you control or while not living in a jurisdiction that taxes individuals on such income.
A company is primarily a financial device to avoid paying (too much) taxes.
Regarding the last part: I don't know if you ever incorporated abroad. But 'streamlined' is an understatement. I have frankly no idea what 'effort' you are referring to. Could you elaborate?
If I register a limited company in Britain but I manage it from France, that company will be taxable in France to a greater or lesser extent. While it may be possible to distribute profits in a more tax-efficient manner, a company cannot operate in a country but completely avoid paying tax by mere fact of being incorporated abroad. Simply employing a contractor or renting a server in a country may be sufficient to fall under the Permanent Establishment rules.
International taxation is punishingly complex. Inadvertent evasion is easy and mistakes expensive. If your company is only paying tax in Hong Kong but has offices or employees elsewhere, you need to contact a competent accountant now.
For example, you could crash on a friend's couch in Barcelona for 6 months and the Spanish government would ask taxes on the income you made during that period from you because that is past the 180 days. Assuming they know you are in the country for that long and can get a hold of you (send you a letter &c.) But you could just make sure you fly to your other friend in Rome and crash on their couch for a bit just before hitting that 180 days mark. ;)
Basically, if you like traveling and write software, just make sure you read the fine print for when non-residents become "residents for tax purposes" in each country you want to stay in for an extended period and make sure you never spend more than the resp. amount of days (i.e. mostly 180 days/fiscal year) in that country and you do not need to pay taxes anywhere -- w/o breaking any law.