PlantText UML Editor: https://www.planttext.com/
Flow Chart
@startuml
(*) --> "A example of a step"
if "Is This is a good example?" then
--> [Yes] "Copy it"
-->(*)
else
--> [No] "Drop it!"
-->(*)
endif
@enduml
Time Sequence (https://plantuml.com/zh/sequence-diagram)
@startuml
participant User
User -> A: 1
activate A
A -> B: 2
activate B
B -> C: 3
activate C
C --> B: end3
destroy C
B --> A: end2
deactivate B
A -> User: end1
deactivate A
@enduml
State Machine (https://plantuml.com/zh/state-diagram)
@startuml
A : A's property
B : B's property
C : C's property
[*] --> A : start to A
[*] --> B : start to B
A --> B : A to B
B --> C : B to C
C --> B : C to B
C --> C : C to C
@enduml
Set arrow color & set contents color
skinparam arrowColor #blue
AAA-->BBB: <color:blue> Description
AAA-[#red]->BBB: Description