As far as small pocket organisers go, the Compact Pen Case from Lihit Lab is pretty small! Despite its size, the well-thought-out layout of its pockets ensures you'll be able to carry a decent number of pens, as well as other items like a mini notebook, Post-Its, a pencil sharpener, eraser etc. On both sides of the case, there's a large pouch that could comfortably hold a large mobile phone.
Lihit Lab Compact Pen Case Yellow Green A7687-6
Lihit Lab - Wide Open Pen Case Smart Fit - Navy (A-7688-11) – Wonder Pens
Lihit lab. Compact Pen Case Yellow Green A7687-6
Water and Stain repellent compact pen case. Able to slip into your bags or pockets. Inner fabric is raised to protect your pens.
LIHITLAB Compact Pen Case, Water & Stain Repellent
Lihit Lab Compact Pen Case Yellow Green A7687-6
Lihit lab. Compact Pen Case Yellow Green A7687-6
Lihit Lab. A-7653 Pen Case Flat-type Wide-size — Harajuku Culture Japan - Stationery Products Store
A-7688 Wide Open Pen Case
LIHITLAB Lichtlab Pen Case Book Type Triple Black A7556-24