Portal
Overview
Each world starts with one portal through which the first Blockhead enters. The portal can subsequently be used to craft items, make in-app purchases, and warp in up to 3 Blockheads.
Crafting
With the proper resources, a portal can be used to "warp in" a variety of. Without upgrades, the only item that can be obtained is a Workbench. With upgrades, a gem pickaxe or various ores or ingots can also be acquired.
In-App Purchases
Upgrades
Portal upgrades require a gem of the correct type and time crystals. The progression of upgrades seems to parallel the rarity of the gems used.