I'm afraid you can't. Here is why:
1. Speedlir Global is an upgrade of Speedlir which adds the Global Translator Module in your Speedlir Account.
2. Since Speedlir Global is only up-sell or upgrade you must have Speedlir FE (Standard) in your account first in order to buy the Speedlir Global.
3. Even if you buy Speedlir Global without buying the Speedlir you wouldn't be able to use Speedlir app because Speedlir Global is dependent on the standard product. So, with only Speedlir Global in your account, you wouldn't be able to login.
Note: In case you bought Speedlir Global without buying the main Speedlir consider buying the standard/main product from our sales page here: http://speedlir.com/fe/