I chose the DHT11 / DHT22 sensor because it reads a couple values and uses digital logic.  The small ESP-01 module only has two digital pins free (GPIO0 and GPIO2). No analog pin is available so using a TMP36 sensor is out.

So what other digital sensors would also work:

• Tilt sensor
• Ultrasonic Sensor
• Passive Infrared Sensor
• Magnetic Contact Sensor
• several others

Changing up the Internet interface and sending readings to Adafruit.io would be great also.  It is all up to you.