The Tinker Rank gives you access to various commands:

• /pc (opens your Pokémon PC)
• /he ctable (Crafting Table)
• /he hat (Puts whatever item you're holding on your head)

You also gain access to the Tinker Kit, which consists of:

• 32x Rare Candy
• 64x Poké Ball
• 48x Great Ball
• 32x Ultra Ball
• 64x Andesite Alloy
• 32x Zinc Ingot
• 16x Brass Ingot
• 16x Polished Rose Quartz
• 1x Super Glue
• 1x Sand Paper

You get the following rewards on Purhcase:

• 1x Standard Traveler's Backpack
• 1x Wrench
• 1x Engineer's Goggles
• 1x Exp. Share